Photo of Velvet Underground playing at the Retinal Circus, credit www.pnwbands.com
The Retinal Circus was a short lived dive that operated in a basement from the summer of 1967 to November3, 1968.
It is known that a number of $1 dances were held at the Retinal Circus during the summer of 1967. The earliest known reference of the Retinal Circus is from Georgia Straight #4 - August 11, 1967.
For physical events that happen at a specific time. For example a concert, or dance performance. If there are multiple shows, you can still duplicate your event to cover them all.